Examples of conventional techniques for determining deterioration of a transfer device are as follows. For example, Patent Literature 1 discloses a deterioration detecting device of a driving mechanism, which detects at least one of a position of a movable member of a motor and a current flowing through a driving source and determines a deterioration state of the driving mechanism based on at least one of a change in the detected position with respect to a target position of the movable member and the detected current.
Patent Literature 2 discloses a monitoring device of a substrate transfer system, which compares data corresponding to a target position of a movable member to data corresponding to an actual position of the movable member which is detected by a detecting means, finds a deviation between these data, and determines that the operation of the transfer system has an abnormality in a case where the deviation exceeds a predetermined allowable range.